Feitz bendee



UNITED STATES PATENT OFFICE.

FRITZ BENDER, OF MUHLHEIM-ON-THE-MAIN, GERMANY, ASSIGNOR TO A. LEONHARDT & 00., OF SAME PLACE.

PRODUCTION OF DlSULPHO-ACID OF DlAMlDO-STI LBENE.

SPECIFICATION forming part of Letters Patent No. 360,553, dated April 5, 1887.

Applicalion filed January 13, 1887. Serial No. 224.254. (Specimens) Patented in England March 29, 1886. No. 4,387, and in France April 19, 1886, No. 175,630.

T 0 aZZ whom it may concern:

Be it known that I, FRITZ BENDER,of MiihL heim-onthe-Main, Grand Duchy of Hesse, in V the Empire of Germany, have invented new 5 and useful Improvements in Sulpho-Acids, of

which the following is a specification.

My present invention relates to certain improvements in the inventions described by my previous Patents Nos. 350,229 and 350,280;

I0 and it consists in the production of disulphoacid of diamidostilbene.

Fifty kilos of the soda salt of paranitro-- toluolsulpho-acid are dissolved in water and digested with aboutfifty kilos of astrong caustic I 5 lye. When the color of the fluid has become an intensive red one, I add zinc dustas much as necessary to render the fluid colorless. I then filtrate it, and precipitate the disulpho-aoid of diamido-stilbene by means of 20 muriatic acid. Instead of reducing with zincdust in an alkaline solution, I can also reduce the red fluid with protochloride of tin and Inuriatic acid. The obtained sulpho-acid is purified by dissolving in soda solution and 2 5 precipitating the filtrate by means of muriatic acid. So manufactured, it forms a yellowish powder which is hardlysoluble in water or spirit, but dissolves easily in alkaline fluids, the so-obtained solutions being precipitated 0 by means of acids. The tetrazo body of the new amido sulpho-acidis hardly soluble in water, and when combined with aromatic amines or phenoles renders yellow, red, or violet coloring-matters, which can be fixed on cotton 5 without any Inordant.

The tetrazo body when treated with protochloride of tin renders a hydrazine derivative. out of which the nitrogene can be eliminated by boiling with asolution of sulphate of copper. The filtrate contains a disulpho-acid from which stilbene can be obtained by distilling the soda salt of this disulpho-acid with soda lime, (natron kalk.)

Having thus described my invention and the manner of employing the same, what I claim, and desire to secure by Letters Patent of the United States of America, is-

1. The production ofdisulpho-acid of (lianlido-stilbene by treating the soda salt of para nitrotoluolsulpho-acid with caustic lye, and reducing the so-obtained red product of condensation with zinc-dust in an alkaline solution or with protochloride of tin in an acid FRITZ BENDER.

\Vitnesses:

FRANZ HASSLACHER, JosEPII PATRICK. 

